Abstract
This study sought to determine whether mesenchymal stem cells-derived extracellular vesicles (MSCs-EVs) carrying microRNA-378a-3p (miR-378a-3p) could affect the pathogenesis of inflammatory bowel disease (IBD) by regulating the GATA-binding protein 2 (GATA2)/aquaporin-4 (AQP4)/peroxisome proliferator-activated receptor α (PPAR-α) axis. Initially, colon mucosa biopsy tissues were harvested from healthy controls and patients with IBD for qRT-PCR and immunohistochemistry analysis. EVs harvested from MSCs and lipopolysaccharide (LPS) were used to stimulate the M064 cells to establish an in vitro inflammation cell model. Besides, 2,4,6-trinitrobenzene sulfonic acid intracolon administration was performed to establish in vivo IBD mouse models. After loss- and gain-of-function assays, the regulatory role of MSCs-derived EVs loaded with manipulated miR-378a-3p in IBD in relation to GATA2/AQP4/PPAR-α were explored. Upregulation of GATA2 was identified in the colon tissue of IBD patients. GATA2, which was a target gene of miR-378a-3p, transcriptionally upregulated AQP4. After silencing of GATA2, LPS-induced apoptosis of M064 cells was reduced by the downregulation of AQP4. Decreased AQP4 contributed to PPAR-α pathway inactivation and weakened the LPS-induced apoptosis of M064 cells. MSCs-EVs delivering miR-378a-3p suppressed the GATA2/AQP4/PPAR-α pathway, which reduced LPS-induced apoptosis of M064 cells and the occurrence of IBD in mice. Altogether, the current study illustrated that MSCs-EVs transfer miR-378a-3p to reduce the GATA2 expression, which downregulates AQP4 to block the PPAR-α signalling pathway, thus suppressing the occurrence of IBD.